oo-

¹

1. a combining form meaning “egg,” used in the formation of compound words.

   oogamous.

o'o

²

Or 'ō·'ō

[oh-oh]

noun

plural

o’os 

1. any of several species of Hawaiian birds of the extinct genus Moho, especially the extinct M. nobilis (Hawaiian o'o ), which had black plumage and two tufts of yellow plumes used to make ceremonial robes for the Hawaiian kings. The last surviving species was M. braccatus (Kauai o'o ), classified as extinct in 1987.

oo-

combining form

1. egg or ovum

   oosperm

Word History and Origins

Origin of oo-¹

< Greek ōio-, combining form of ōión egg ¹

Origin of oo-²

First recorded in 1885–90; from Hawaiian ʿōʿō

Word History and Origins

Origin of oo-¹

from Greek ōion _egg ¹

When To Use

What does oo- mean?

Oo- is a combining form used like a prefix meaning “egg.” It is used in many scientific terms, especially in biology.Oo- comes from the Greek ōión, meaning “egg.” The Greek ōión helps form the word ōophóros, meaning “egg-bearing” and is the source of the combining form oophoro-, used to indicate the ovary.Distantly related to the Greek ōión is the Latin word for egg, ōvum, source of the related combining forms ov-, ovi-, and ovo-, also used to mean “egg.” The Latin ōvum is ultimately the origin of ovario-, used, like oophoro-, to mean “ovary.”What are variants of oo-?When combined with words or word elements that begin with a vowel, oo- becomes o-, as in oidium.